Dr. Adel Elshimy. Students at the end of the lecture will be able to : Describe the applied anatomy of the airway. Conduct a preoperative airway assessment.

Dr. Adel Elshimy

Students at the end of the lecture will be able to :

Describe the applied anatomy of the airway. Conduct a preoperative airway assessment . Identify a potentially difficult airway. Learn about management of airway

obstruction. Become familiar with airway equipment. Understand issues around aspiration

prophylaxis. Become familiar with controlled ventilation. Appreciate ways of monitoring of ventilation

and oxygenation.

Opening the Airway

Jaw thrust Head tilt–chin lift

Oropharyngeal Airway

Proper size

Oropharyngeal Airway (cont.)

Nasopharyngeal Airway (cont.)

Bag-Valve-Mask (cont.)

With oxygen reservoir

A = esophageal obturator; ventilation into trachea through side openings = B

C = tracheal tube; ventilation through open end if proximal end inserted in trachea

D = pharyngeal cuff; inflated through catheter = E

F = esophageal cuff; inflated through catheter = G

H = teeth marker; blindly insert Combitube until marker is at level of teeth

Distal End

Proximal End

B

C

D

E

F

G

H

A

Innervation Vagus n.

◦ Superior laryngeal n. External branch – motor

to cricothyroid m. Internal branch –

sensory larynx above TVC’s

◦ Recurrent laryngeal n. Right – subclavian Left – Aortic arch (board

question) Motor to all other

muscles, Sensory to TVC’s and trachea

Resuscitation (CPR) Prevention of lung soiling Positive pressure ventilation (GA) Pulmonary toilet Patent airway (coma or near coma) Respiratory failure(CO2 retention )

I-History: previous history of difficulty is the best

predictorInquire about:-Nature of difficulty -No of trials -Ability to ventilate bet trials -Maneuver used -ComplicationsII-Snoring and sleep apnea .III-Predictors of DMV (obese ) .

-Look for any obvious anomaly Morbid obesity(BMI) Skull Face Jaw Mouth,teeth Neck

I-The 3 joints movements A-O joint(15-20 degrees)Presence of a gap bet the Occiput and C1 is essential The cervical spine(range>90) T.M joint:Subluxation (1 finger)

Mouth opening: 3 fingersThyromental distance: >6.5cm

Sternomental distance >12.5cm .

Mallampatti test:Based on the hypothesisThat when the base of theTongue is disproportionallyLarge it will overshadow thelarynx

-Simple easy test,correlates with what is seen during laryngoscopy or Cormack-Lehene grades ,but

1-moderate sensitivity and specificity(12% false +ve)2-Inter observer variation3-Phonation increases false negative view

Apparent cause e.g. goitre OSA Noisy breathing or stridor Signs of upper airway obstruction Other causes

Prior condition Surgery Rheumatoid

arthritis Osteoarthritis Short muscular

neck .

-Bag and mask,oxygen source-Airways oro and nasopharyngeal-Laryngosopes different blades-ETT different sizes-suction on

Induction of anesthesia produces upper airway relaxation and possible collapse

Holding the mask C-E manuever.

1-Normal roomy mandible

2-Normal T-M, A-O , and C-spine

3-Alignment of 3 axes orAssuming sniffing position

-Any anomaly in these 3 jointsA-O, T-M or C-spine can resultIn difficult intubation

Look for epiglottis◦ If initially not found

insert laryngoscope further

◦ If this maneuver does not work slowly pull laryngoscope back

Once epiglottis visualized, push laryngoscope into vallecula and apply traction at 45 degree angle to “push” epiglottis up and out of the way

Direct visualization of ETT between cords Continuous trace of capnography 3 point auscultation Bronchoscopy ;carina seen Esophageal detector device Other as bilateral chest movement,mist in

the tube,CXR

Indications Technique: -Preoxygenation -IV induction with sux -Cricoid pressure -Intubate, inflate the cuff ,confirm position -Release cricoid and fix the tube

Cricoid Pressure

1-Inadequate ventilation

2-Esophageal intubation

3-Airway obstruction4-Bronchospasm5-Aspiration6- Trauma7-Stress response

❏ Too long - endobronchial intubation❏ Too short - accidental extubation❏ Too large - trauma to surrounding tissues❏ Too narrow - increased airway resistance❏Too soft - kinks❏ Too hard - tissue damage❏ Prolonged placement - vocal cord granulomas,

tracheal stenosis❏ Poor curvature - difficult to intubate❏ Cuff insufficiently inflated - allows leaking and

aspiration❏ Cuff excessively inflated - pressure necrosis

Causes-Congenital

-Acquired

Bullard Wu Scope

Upsher GlideScope

Expected from history,examinationSecure airway while awake under LA

Unexpected different optionsPriority for maintenance of patent airway and

oxygenation

Spontaneous ventilation Controlled ventilationPressure cycled and volume cycled ventilator-Tidal volume 10 mls/kg-Respiratory rate to maintain normocarbia-I:E ratio -PEEP

Adequate airway assessment to pick up expected D.A to be secured awake

Difficult intubation cart always ready Pre oxygenation as a routine

Maintenance of oxygenation not the intubation should be your aim

Use the technique you are familiar with Always have plan B,C,D in unexpected D.A

General guidelines: check that neuromuscular function and hemodynamic

status is normal check that patient is breathing spontaneously with

adequate rate and tidal volume allow patient to breathe 100% O2 for 3-5 minutes suction secretions from pharynx deflate cuff, remove ETT on inspiration (vocal cords

abducted) ensure patient breathing adequately after extubation ensure face mask for O2 delivery available proper positioning of patient during transfer to recovery

room, e.g. sniffing position, side lying.

Nasal cannulae◦ inspired oxygen concentration is dependent on the

oxygen flow rate, the nasopharyngeal volume and the patient’s inspiratory flow rate.

◦ Increases inspired oxygen concentration by 3-4%. ◦ Oxygen flow rates greater than 3 liters are poorly

tolerated by patients due to drying and crusting of the nasal mucosa.

Nasal cannulae

Face masks : ◦ Three types of facemask are available; open,

Venturi, non-rebreathing. Open facemasks :

◦ Are the most simple of the designs available. ◦ They do not provide good control over the oxygen

concentration being delivered to the patient causing variability in oxygen treatment.

◦ A 6l/min flow rate is the minimum necessary to prevent the possibility of rebreathing.

◦ Maximum inspired oxygen concentration ~ 50-60%.

Venturi facemasks They should be used in

patients with COPD/emphysema where accurate oxygen therapy is needed.

Arterial blood gases can then be drawn so correlation between oxygen therapy for hypoxemia and potential risk of CO2 retention can be made.

Masks are available for delivering 24%, 28%, 35%, 40%, 50%.

Non-rebreathing facemasks ◦ have an attached reservoir

bag and one-way valves on the sides of the facemask.

◦ With flow rates of 10 liters an oxygen concentration of 95% can be achieved.

◦ These masks provide the highest inspired oxygen concentration for non-intubated patients.

Dr. Adel Elshimy

Date: 7/1/2014

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